Driver assistance systems such as ACC (Adaptive Cruise Control) or collision warning systems (PSS, Predictive Safety Systems) require a sensor system in order to acquire the surrounding traffic situation, in particular in order to locate vehicles traveling in front. This sensor system typically includes a radar sensor or a video camera having an associated electronic image evaluation system, or also a combination of both sensor systems. Such a combination is particularly useful because the specific strengths of the different sensor systems supplement one another. Thus, a radar sensor enables, in general, a precise measurement of radial distances and radial speeds, but only a relatively low-resolution measurement of azimuth angles, and only a rough estimation of the width of located objects, whereas a video camera permits precise measurement of azimuth angles, cross-speeds, and object widths, but (in particular in the case of a monocular system) offers only a low degree of precision in the measurement of radial distances and speeds.
German patent document DE 10 2007 018 470 A1 discusses a sensor system that includes a combination of a radar sensor and a video camera, and an electronic evaluation system that fuses the data of the two sensor types with one another.
In available sensor assemblies, the radar sensor is standardly attached to the outside of the vehicle, usually in the area of the front bumper. The video camera, on the other hand, is typically situated inside the vehicle, behind the windshield.
An object of the exemplary embodiments and/or exemplary methods of the present invention is to create a sensor assembly of the type described above that can be particularly easily installed and adjusted.
According to the exemplary embodiments and/or exemplary methods of the present invention, this object may be achieved in that the radar sensor and the video camera are integrated into a common housing.
The radar sensor and the video camera should in general be adjusted so that their optical axes run exactly parallel to one another, for example exactly in the longitudinal direction of the vehicle. The integration of the radar sensor and the video camera in a common housing makes it possible to carry out this adjustment of the two components relative to one another at the manufacturer with a high degree of precision. During installation in the motor vehicle, the housing then need only be mounted in or on the vehicle body and adjusted relative to the body, thus significantly simplifying the assembly and adjustment processes. For example, the adjustment relative to the vehicle body can take place on a suitable test bench with the aid of the video image recorded by the video camera itself, whereby at the same time a correct adjustment of the radar sensor relative to the vehicle body is also achieved.
The common housing can for example be attached in the interior of the vehicle, behind the windshield, as the video camera was previously.
Advantageous embodiments and developments of the present invention are described herein.
In a particularly advantageous specific embodiment, the common housing contains electronic components for a common pre-evaluation of the data of the radar sensor and of the video camera. In this case, the fusion of the data can already take place at a low level, namely at the sensor level, using the electronic components in the common housing, the data of the radar sensor facilitating the interpretation of the video image and vice versa, so that the amount of data to be communicated from the housing to the rest of the vehicle electronics system can be significantly reduced.
An exemplary embodiment of the present invention is shown in the drawings and is explained in more detail in the following description.